Section 45 of the Competition and Consumer Act prohibits contracts, arrangements, understandings or concerted practices that have the purpose, effect or likely effect of substantially lessening competition in a market, even if that conduct does not meet the stricter definitions of other anti-competitive conduct such as cartels.

Like all businesses, professionals and their associations must compete fairly and avoid engaging in anti-competitive behaviour such as cartels, exclusive dealing, unfair dealing or unconscionable conduct.

It is illegal for competitors to work together to fix prices rather than compete against each other. This conduct restricts competition, and can force prices up and reduce choices for consumers and other businesses.

Bid rigging, also referred to as collusive tendering, occurs when two or more competitors agree they will not compete genuinely with each other for tenders, allowing one of the cartel members to ‘win’ the tender. Participants in a bid rigging cartel may take turns to be the ‘winner’ by agreeing about the way they submit tenders, including some competitors agreeing not to tender.